As an example of a semiconductor integrated circuit device, a nonvolatile storage device, designated as, for example, a flash memory or an EEPROM (Electrically Erasable Programmable Read Only Memory), is known. As an example of a flash memory, there is a memory cell of a one-transistor system in which the memory cell is composed of one nonvolatile storage element, or a memory cell of a two-transistor system in which one nonvolatile storage element and one selecting MISFET (Metal Insulator Semiconductor Field Effect Transistor) are connected in series. Whereas, for the nonvolatile storage element, there is a floating gate type in which information is stored in a floating gate electrode between a semiconductor substrate and a control gate electrode, a MNOS (Metal Nitride Oxide Semiconductor) in which a NO (Nitride/Oxide) film is used as a gate insulating film between a semiconductor substrate and a gate electrode, so that information is stored in this gate insulating film, and a MONOS (Metal Oxide Nitride Oxide Semiconductor) type in which an ONO (Oxide/Nitride/Oxide) film is used as a gate insulating film between a semiconductor substrate and a gate electrode, so that information is stored in this gate insulating film, or the like. Further, for the floating gate type, there is also one using an ONO film for an interlayer insulating film between a floating gate electrode and a control gate electrode.
On the other hand, in the semiconductor integrated circuit device, not only active elements, such as MISFETs, but also passive elements, such as resistor elements and capacitor elements, are generally present in a large number. These elements are used in, for example, a delay circuit, a load element, an oscillation circuit, and a bypass capacitor for stabilizing the power supply. Also, for resistor elements and capacitor elements, ones having various structures are known. For example, as resistor elements, there are a diffused resistor element formed by doping impurities into the semiconductor substrate and a polycrystal silicon resistor element formed of a polycrystal silicon film. As capacitor elements, there are a capacitor element in which a semiconductive region (impurity diffused region) formed by doping impurities into a semiconductor substrate serves as a lower electrode, and a conductive film disposed over the lower electrode via a dielectric film interposed therebetween serves as an upper electrode, and a capacitor element in which a conductive film disposed over an element isolation region of a principal surface of a semiconductor substrate serves as a lower electrode, and a conductive film disposed over the lower electrode via a dielectric film interposed therebetween serves as an upper electrode, and the like. Whereas, for the capacitor element, a capacitor element using the ONO film described above as a dielectric film is also known.
Incidentally, documents regarding the present invention include the following: Patent Document 1 (Japanese Unexamined Patent Publication No. 2000-269449) and Patent Document 2 (Japanese Unexamined Patent Publication No. 2000-164835). Patent Document 1 discloses a manufacturing technique for use in the fabrication of a semiconductor integrated circuit device having a nonvolatile memory of a floating gate structure, and a capacitor element. Patent Document 2 discloses a manufacturing technique for use in the fabrication of an integrated circuit having a nonvolatile memory of a floating gate structure, a high breakdown voltage transistor, and a low breakdown voltage transistor.
[Patent Document 1]
Japanese Unexamined Patent Publication No. 2000-269449
[Patent Document 1]
Japanese Unexamined Patent Publication No. 2000-164835